Operational amplifier and pipeline ad converter

Abstract

A differential voltage interconnect (W 101 a ) electrically connects the gate electrode of a transistor to be used among differential transistors (T 101 a , T 101 a , . . . ) to an input node receiving an input voltage (Vinn), and a differential voltage interconnect (W 101 b ) electrically connects the gate electrode of a transistor to be used among differential transistors (T 101 b , T 101 b , . . . ) to an input node receiving an input voltage (Vinp). A bias voltage interconnect (W 102 ) electrically connects the gate electrode of a transistor to be used among current source transistors (T 102 , T 102 , . . . ) to a bias node receiving a bias voltage (VBN), and a bias voltage interconnect (W 103 ) electrically connects the gate electrodes of transistors to be used among load transistors (T 103 a , T 103 a , . . . , T 103 b , T 103 b , . . . ) to a bias node receiving a bias voltage (VBP).

1 - 11 . (canceled) 
     
     
         12 . A pipeline AD converter comprising a plurality of conversion stages,
 wherein each of the plurality of conversion stages includes:   an analog-digital conversion circuit for converting an input differential voltage from the preceding stage to a digital value;   a digital-analog conversion circuit for converting the digital value obtained by the analog-digital conversion circuit to an intermediate differential voltage; and   a charge operation circuit having a capacitance section for sampling the input differential voltage and a differential amplification section for amplifying a mixed differential voltage of the input differential voltage sampled by the capacitance section and the intermediate differential voltage obtained by the digital-analog conversion circuit, and   the differential amplification section includes a plurality of operational amplifiers having the same configuration.   
     
     
         13 . The pipeline AD converter of  claim 12 , wherein each of the plurality of conversion stages further includes:
 an input switch circuit for connecting an input terminal pair of each of the plurality of operational amplifiers to either one of an OFF voltage node for receiving an OFF voltage for turning OFF the operational amplifier and the capacitance section; and   an output switch circuit for switching the connection between an output terminal pair of each of the plurality of operational amplifiers and an output node for outputting an output voltage of the conversion stage.